Terminals of this type are already known for paying-in (i.e. a financial transaction) subsequent to a commercial transaction. There also exist terminals capable of filling-in a blank check, and in particular of filling-in the amount to be paid, so that the customer only has to sign. However, such terminals remain unsatisfactory, in that the shopkeeper must still manually key-in customer details for accounting purposes. Also, banking operations on checks (and in particular clearing house operations), are expensive and any simplification thereto would be welcome.